There are two types of enlarged thyroid issues that can occur within dogs, and they are categorized as being either primary or secondary in nature. Primary thyroid issues originate within the actual thyroid itself. Secondary thyroid issues in dogs occur resulting from problems beginning elsewhere, such as in the pituitary gland. The most common problem leading to an enlarged thyroid in dogs is hypothyroidism. Thyroid issues can unfortunately appear like other health issues in dogs.
Physical signs associated with an enlarged thyroid in dogs include weight gain without a change in diet, stiffness in the muscles and overall weakness. A dog with an enlarged thyroid may also experience constipation or incontinence, intolerance to cold and seizures.
Appearance symptoms associated with an enlarged thyroid in dogs include a dull or dry coat with hair that easily pulls out, hair loss in the area around the tail and dandruff. Dogs with an enlarged thyroid may also present with thick, dry or oily skin and chronic skin infections or chronic ear infections.
A dog with an enlarged thyroid may appear to be lethargic, or it may become tired more easily. A dog with an enlarged thyroid may appear unwilling to exercise, mentally dull, lacking in libido or depressed. Dogs with enlarged thyroid glands may also be more aggressive, more compulsive, anxious, phobic, passive or hyperactive.
A standard veterinarian examination may also uncover symptoms of an enlarged thyroid gland in dogs, including a slowed heart rate, or a heart rhythm that is abnormal in some other way.
A veterinarian may perform a blood test on your dog to indicate other potential symptoms of an enlarged thyroid. Some of the symptoms that may appear as a result of this blood test include a low T3 level or low T4 level, an elevated TSH level, high cholesterol between 65 and 75 percent of all cases, anemia in approximately 36 percent of all cases and positive antibody levels for hyperthyroidism.